Rotating separator with distribution and mixing means



Sept. 11, 1962 c. M. DOYLE ETAL 3,053,440

ROTATING SEPARATOR WITH DISTRIBUTION AND MIXING MEANS Filed March 4,1959 I TORS: WM 'Q flaw 4 ATZORNE United States Patent Ofiice 3,053,440Patented Sept. 11, 1962 3 053 440 ROTATING SEPARA IOR WITH DISUTION ANDMIXING MEANS Collin M. Doyle, Chicago, and Herbert R. Kaiser, EvergreenPark, Ill., assignors, by direct and mesne assignments, to Walter J.Podbielniak, Chicago, Ill.

Filed Mar. 4, 1959, Ser. No. 797,211 3 Claims. (Cl. 233--15) Thisinvention relates to a rotating separator with distribution and mixingmeans. The combination of the present invention has utility inconnection with rotating contactors where the final clarification of oneor both phases presents a problem. For example, the present invention isapplicable to rotating contactors like those described in prior Patents2,758,783 and 2,758,784.

In the design and operation of rotating devices of the kind described inthe patents just cited, it has heretofore been assumed that theprincipal problem was to obtain adequate mixing of the phases beingcontacted, and that the separation or clarification of the phases wouldbe readily taken care of by virtue of the very large centrifugal forcescreated by the high speeds of rotation. The high centrifugal forcescreated by the rotation of the devices does tend to produce a separationof the light and heavy phases as would be expected. However, there is anoffsetting factor which heretofore has not been adequately taken intoaccount. The rotation of the device tends to cause the liquids to swirlaround in circumferential paths which leads to intermixing of the phasesand opposes their separation. At the high speeds of rotation normallyemployed, the liquid phases may be brought into turbulent flow due tothis rotary swirl action. Consequently, this type of action, which hasnot heretofore been fully understood or appreciated, may greatlycomplicate the problem of separating or clarifying the phases, and thisproblem is especially acute where the phases tend to emulsify, wheresolids are present in the liquid phases, or where the liquid phases areof relatively high viscosity.

It is therefore an object of the present invention to provide a devicewhich has application as a combination contactor and separator whereinthe rotary swirl action is taken advantage of for the purpose ofdistributing and/ or mixing the liquids being processed while at thesame time minimizing this action in connection with the separation orclarification of the liquid phases. Further objects and advantages willappear as the specification proceeds.

A typical application of the present invention is illustrated in theaccompanying drawing, in which FIGURE 1 is a front elevational view of arotating device embodying the present invention, portions of the rotorand shaft being broken away to more clearly show the construction of theinternal elements;

FIGURE 2 a perspective View of one of the swirl-arresting disks employedin the device of FIGURE 1;

FIGURE 3 a perspective view of one of the perforated rings whichfunction as mixing and distributing elements in the device of FIGURE 1;and

FIGURE 4, a perspective view of one of the swirlarresting rings employedin the device of FIGURE 1.

In the device of FIGURE 1 there is shown a rotor casing which is mountedco-axially on a shaft 11 and provides a radially-extending chamber 12therein. Shaft 11 extends horizontally and is rotatably-mounted on abase 13 by means of suitable bearings (not shown in section). A case 14extends above base 13 to complete the enclosure of the rotor 10. As iswell-known in the art, means is provided for driving the shaft 11 at acontrolled rotational speed, and conduits are connected to stationaryshaft extensions 15 and 16 for the introduction and removal of liquidsthrough passages in the shaft. In the illustration given, for example,the liquid phase of lighter density can be supplied to shaft passage 17through a seal 18 which permits shaft 11 to rotate while extension 15remains stationary. In a similar manner the heavy phase can be suppliedto shaft passage 19 through a seal corresponding to seal 18' (notshown). The heavy phase can be removed through shaft 21 and seal 22, andthe light phase through shaft passage 23 and a seal corresponding toseal 22 (not shown). Since this invention relates to the internalconstruction of the rotor and the rest of the device can be constructedin a manner previously known and described, it is not believed that itwill be necessary to further discuss the details of construction of thedevice of FIGURE 1 other than those of the rotor itself. In thisconnection, reference is made to prior patents on similar devices whichcontain disclosures supplementing the foregoing brief description, suchas the disclosures of Patents 2,578,783 and 2,578,784.

Turning now to the specific subject matter of the present invention, itcan be seen in FIGURE 1 that the rotor 10 includes a number of elementswithin chamber 12. These elements include inlet tubes 24 and 25, aspill-over disk 26, a group of axially spaced-apart partition walls 28,and a second group of axially spaced-apart partition walls 29. In theillustration given, the inlet tubes 24 and 25 are arranged inoppositely-disposed pairs. The tubes 24 and 25 respectively provideinternal passages 30 and 31 which communicate with passages within shaft11, the passages 30 communicating with shaft passage 17 and the passages31 with shaft passage 19. With this arrangement, the inlet tubes 24 canbe used for supplying the light phase to rotor chamber 12 and the inlettubes 25 for the heavy phase.

It will also be noted that in the embodiment shown in the drawing,casing 10 is of a cylindrical configuration, being formed of acylindrical outer band or wall 10a and end plates 10b and Ida. The endplates 10b and 10's are received within recesses in the outer ends ofband 10a and are welded thereto as well as to shaft 11, which in theillustration given extends through rotor chamber 12. It will beunderstood that this provides a sealed casing aroundchamber 12.

In the illustration given, spill-over disk 26 terminates short of theinside of band 1% and is spaced inwardly from end wall 10!) to provide apassage 32 for the removal of the heavy phase, the passage 32 beingarranged to communicate with shaft passage 21. In the illustrationgiven, lateral passages 33 connect passage 32 with passage 21. Shaftpassage 23 which can be used for the removal of the lighter phasecommunicates with the inwardmost portion of rotor chamber 12 throughlater passages 34.

In accordance with the present invention, the group of radially spacedpartition walls 28 are arranged to occupy a zone outwardly of shaft 11and inwardly of the radially outermost wall portion of casing 10. Thesepartition walls provide passages 35 therebetween which extend axiallyand circumferentially. Partition walls 28 provide openings for the flowof liquids along radial paths, thereby permitting liquids to flow intothe innermost and outermost of the spaces 35 between the walls, and thento traverse the zone occupied by the partition walls. In theillustration given, partition walls 28 are in the form of concentriccylinders which are arranged coaxially with shaft 11 and are providedwith a plurality of perforations or holes 36, as shown in FIGURE 3.Rings 28 can be held in position by having their outer ends receivedwithin grooves in end plate 10c and spillover disk 26.

The zone occupied by the partition walls 28 constitutes the distributingand mixing section of the rotor chamber. In the illustration given, thissection is defined by five of the partition walls 28. However, it may beunderstood that more of the partition walls can be provided and that thezone can be enlarged. The design illustrated in FIGURE 1 is especiallyadapted for the processing of two liquid phases where the principalproblem is the clarification of the light phase which is present inrelatively large volume compared to the heavy phase. In the illustrationgiven, the clarifying area for the light phase is the zone occupied bythe partition walls 27, while the clarifying area for the heavy phase isthe zone occupied by the partition walls 29. For the processing ofliquid phases where the heavy phase was present in larger volume thanthe light phase, the extent of the zone occupied by partitions 29 wouldbe correspondingly enlarged while the extent of the zone occupied by thethe partitions 27 would be diminished. Where additional mixing wasrequired, as where a plurality of stages was needed, the extent of thezone occupied by the partition walls 28 would be increased. It willtherefore be understood that the relative size of the various zoneswithin the rotor chamber 12, as defined by the partition walls 27, 28,and 29, can be varied considerably without departing from the principlesof the present invention.

In accordance with the present invention, axiallyspaced partition walls,such as walls 27 and 29, are provided in combination with the radiallyspaced partition walls, such as partition walls 28. In other words, thepresent invention contemplates the use of axiallyspaced partition wallswithin chamber 12 which are arranged to occupy a zone radially-spacedfrom the zone of the group of radially-spaced partition walls. Where itis desired to promote the complete and rapid clarification of bothphases, this can be done by employing two groups of axially-spacedpartition walls as in the illustration given, one group being positionedinwardly of the radially-spaced partition walls and the other groupbeing positioned outwardly thereof. However, the inwardly positionedgroup of partition walls can be used independently of the outwardlypositioned group. For example, where the heavy phase presents no problemwith regard to its complete clarification, the partition walls 29 can beomitted, and the partition walls 27 used alone in combination with thepartition walls 28.

For the purpose of the present invention there is associated with theaxially-spaced partition walls, such as the walls 27 and 29, means, suchas baffles or vanes, for at least partially blocking the circumferentialflow of liquids between the partition walls while permitting the liquidsto flow along radial paths. Preferably, a plurality of such vanes orbaffies are positioned between each of the axially-spaced partitionwalls. In the illustration given, the partition walls 27 are in the formof disks which are coaxially received on shaft 11. As shown more clearlyin FIGURE 2, the disks 27 have a central opening 37 through which theshaft 11 extends. A plurality of radially extending vanes 38 are mountedon one face of the disks 27 to define segments 39 therebetween. In theillustration given, the vanes 38 are in the form of straight rods whichare welded to the disks 27. The vanes or rods 38 need not be straight,and can be curved in various arcuate shapes, such as a convolute shape,a spiral shape, etc. In order to prevent any unequal pressures fromdeveloping in the spaces 39 between the disks 27, the intermediateportions of the disks are provided with a few openings, such as openings40 (FIGURE 2). Also, the disks 27 are provided with spaced serrations 41around central opening 37. When the disks are arranged on shaft 11 inthe manner shown in FIGURE 1, the serrations 41 provide ports throughwhich the clarified light phase can flow 7 rings. A plurality of vanes42 are mounted on one side of the rings. As with the partition walls 27,the vanes may be in the form of straight rods which are arranged toextend radially and are attached to the partition wall by welding. Thisis the construction shown in FIGURE 4 where the rod-like vanes 42 arewelded to the rings 29. It will be understood from what has beenpreviously said that the vanes 42 should extend outwardly so as todefine partially enclosed segments therebetween, such as segments 43.The vanes themselves, however, do not need to be straight nor do theyneed to be arranged on precisely radial lines.

In the illustration given, the outer edge of partitions 29 are providedwith spaced serrations 44. When the partitions 29 are arranged in themanner shown in FIGURE 1 with their outer edges abutting the outer wallof casing 19, the serrations 44 define ports through which the clarifiedheavy phase can flow axially from the spaces 45 between walls 29 todischarge passage 32 for removal through shaft passage 21.

In the construction of rotors like the one shown in FIGURE 1, the innerpartition walls 27 can be slipped onto shaft 11 through an open end ofthe casing 10, that is, for example, before the attachment of end wall10b. The partition walls center themselves on the shaft and are held inaxially-spaced apart relation by the vanes 38, the vanes being attachedto one side of each of the partition walls and extending into contactwith the adjacent side of the next partition wall. The cylindricalpartition walls 28 can next he slipped on over the partition walls 27.These cylindrical walls may be held in radially-spaced apart relation byhaving their ends received within the grooves of a master end plateuntil they are permanently secured by means of the radially extendingrods and tubes, such as the tubes 24 and 25. If desired, other means canbe provided for holding the cylindrical partition walls inconcentrically spaced relation with respect to each other, such asprojections extending from the rings, dimples formed in the rings, etc.

As a further step in the assembly procedure, the outer partition walls29 can he slipped on over the outermost of the cylindrical partitionwalls 28. The vanes 42 will act as spacers between the walls, the vanesextending from the wall to which they are attached to the adjoining faceof the next adjacent wall. In completing the assembly of the rotor, thespill-over disk 26 can he slipped onto the rotor shaft and movedinwardly to the position shown in FIGURE 1. Both sides of the spill-overdisk can be provided with outwardly extending vanes, such as the vanes38 and 42, and having a similar function to these vanes. For example,the vanes attached to disk 26 would extend into contact with theadjacent partition walls of the groups 27 and 29. Similarly, the vanesextending outwardly on the other side of spill-over disk 26 would engagethe inner face of end wall 10b when it is applied to the rotor. It willbe understood of course that these spacers would be arranged to permitthe radial flow of liquids through outlet passage 32 while tending torestrict the circumferential flow of liquid therein.

It has been previously pointed out that the tubes 24 and 25 providemeans for introducing the liquids to chamber 12. In the illustrationgiven, the tubes 24 can be used for introducing the light-phase, whilethe tubes 25 can be used for introducing the heavy phase. It will beunderstood that the liquid phase of lesser density (the light phase)should be introduced outwardly of the point of introduction of theliquid phase of greater density (the heavy phase). In accordance withthe present invention, the inlet means should be arranged so that atleast part of the radially-spaced partition walls, such as the walls 28,lie between the respective points of introduction of the light and heavyphases. Preferably, at least one of the phases is introduced within thezone defined by the radially spaced partition walls.

The inlet means shown in FIGURE 1 is described more particularly incopending application Serial No. 796,584 filed March 2, 1959, entitledLiquid Feed Arrangement for Centrifugal Devices. Reference isthereforemade to this application for a more detailed description. It isbelieved suflicient for the purpose of the present application toindicate that the tubes 24 and 25 have their inner ends threadedlysecured to shaft 11 and their outer ends connected to casing band a bywelding. Within the tubes there are rotatable sleeves, such as sleeves46 and 47 which provide two or more groups of radially-spaced ports, thegroups being selectively alignable with ports in the tubes 24 and 25'.In the illustration given, the ports 48 of tubes 24 and the ports 49 oftubes 25 are in alignment with the ports 50 and 51 respectively of thetubes 24 and 25-. As described in the above cited application, thesleeves 46 and 47 provide other ports, which are selectively alignablewith radially spaced ports in the inlet tubes, suchas ports 52 and 53.In the illustration given, the heavy phase would flow outwardly fromtube passages 31 to ports 49 and 51 into the portion of rotor chamber 12just inwardly of the innermost partition wall of the group of partitionwalls 28. Similarly, the light phase would flow outwardly from thepassages '30 through the ports 48 and 50 into the outermost space 35within the group of partition walls 28. If it is desired to vary theposition of one or both inlets, this can be done by removing thethreaded closure plugs 54 and 55, and manipulating the sleeves 46 and 47to disalign the ports 49 and 48 with the ports with which they are nowaligned and bring other ports into alignment with the two ports 52 and53. If this were done, both the light and heavy phases would beintroduced within the spaces 35 provided by the cylindrical partitions28. Alternatively, the position of the heavy and light phases inlets canbe varied independently, providing the heavy phase is not releasedoutwardly of the light phase so that there is no contact therebetween.When it is desired to provide a plurality of stages, the points ofintroduction of the phases may be separated by a plurality of partitionwalls.

In the operation of the device, the mixing of the phases is promoted bythe rotary swirl action which occurs within the spaces 35 between thecylindrical partition walls 28. On the other hand, this action isreduced to a minimum in the clarification Zones. For example, the lightphase moves toward shaft 11 by flowing inwardly through the spaces 39between the disks 27. At the same time, portions of the liquid arecaptivated within the segmental spaces 39, thereby preventingcircumferential flow of the liquids. Similarly, the heavy phase iscaptivated within the segmental spaces 43 provided by partitions 29 andvanes 42. In this way, the clarification of the light phase and theheavy phase, are both as promoted, and the tendency of the phases to becontinually remixed due to rotational swirl is substantially overcome.

As an example of the two procedures just described, the water washing ofalkali-refined vegetable oils can be mentioned. Followingalkali-refining the vegetable oils contain a small proportion of soapand residual alkali, which is commonly removed by a procedure known aswater washing. With the device shown in FIGURE 1, the vegetable oil tobe treated could be introduced through the tubes 24, and the wash waterthrough the tubes 25. The water would be thoroughly mixed with the oilwithin the zone defined by the cylindrical partitions 28, the soap andresidual alkali being removed into the water phase, which would thenflow outwardly into the zone defined by the outer partition walls 29,and after being clarified within this zone would be removed through theheavy phase outlet passage 32. The oil, being the larger volume phase,and the more difiicult to clarify, flows inwardly through the relativelylarge zone defined by partition walls 27, and the clarified oil isremoved from the innermost portion of the zone through the shaftpassages 34. Flowing inwardly through the clarifying zone, thepartitions 27 and the vanes 38 will act; to arrest any tendency of theoil to remixwith the water phase from which it is being separated, thepartition walls and vanes functioning to prevent rotational swi-rl inthe manner previously described. This has particular advantage inconnection with the clarification ofa light phase, such as the oil inthe process just described. The centrifugal force created by therotation of the device is considerably smaller within the light phaseclarifying zone which adjoins the shaft than it is within the heavyphase clarifying zone which is at a considerable radial distance fromthe shaft. Consequently, it is more difiicult for the centrifugalseparating force to overcome a tendency toward remixing which isproduced by a rotational swirl action.

While in the foregoing specification this invention has been describedin relation to a specific embodimentthereof for purpose of clarity, itwill be apparent to those skilled in the art that the inventiondescribed herein is of wide scope and is capable of application in manyother specific embodiments. Furthermore, it will be apparent that manyof the specific details hereinbefore described can be variedconsiderably without departing from the basic principles of theinvention.

We claim:

1. In a centrifugal apparatus for countercurrently contacting andseparating liquid phases of different densities, said apparatus being ofthe kind including a rotatablymounted horizontally-extending shaftproviding a plurality of liquid fiow passages therein, liquid seals ateach end of said shaft to permit liquids to be introduced into andremoved from said shaft passages while said shaft is rotating, and arotor casing mounted ccaxially on said shaft between said seals andproviding a cylindrical chamber therein, the combination comprising agroup of concentric rings arranged in radially-spaced apart relationwithin said rotor chamber and coaxial to said shaft to provide acontacting and mixing section, said section occupying a zone outwardlyof said shaft and inwardly of the radially outermost wall portion ofsaid casing, said rings providing open cylindrical spaces betweenadjacent rings which extend axially across said contacting and mixingsection and entirely around said rings so that liquids can flow freelyacross and around said spaces, thereby promoting the mixing and intimatecontacting of said liquid phases within said section, said rings havingopenings therethrough for the flow of liquids along radial paths inpassing between said cylindrical spaces, a group of outwardly-extendingpartition walls arranged wi hin said rotor chamber in axially-spacedapart relation to provide a clarifying section, said clarifying sectionoccupying a zone radially-spaced from said contacting and mixingsection, said partition walls having a plurality of swirl arrestingbaflles extending therebetween, said baffles dividing the spaces betweensaid partition walls into a plurality of radially-extending openendedsegments, thereby permitting the flow of liquids along radial pathswhile restricting the circumferential fiow of liquids, said open-endedsegments communicating at one end with the nearest cylindrical space ofsaid contacting and mixing section, said rotor and shaft providingoutlet means extending between the other ends of said open-endedsegments and one of said passages within said shaft, said rotor andshaft having a second outlet means providing communication between asecond of said shaft passages and the cylindrical space of saidcontacting and mixing section which is furthest away from saidclarifying section, and said shaft and rotor also providing inlet meansfor separately supplying a light liquid phase and a heavy liquid phasefrom additional ones of said shaft passages to said rotor chamber, saidinlet means introducing said heavy phase at a place outwardly of saidshaft and radially inwardly of the place of introduction of said lightphase, and said places of introduction for said light and heavy phasesbeing separated by at least part of said rings.

2. The centrifugal apparatus of claim 1 wherein said group of partitionwalls occupies a zone between said shaft and said contacting and mixingsection, said partition walls extending outwardly from said shaft towardsaid rings.

3. In a centrifugal apparatus for countercurrently contacting andseparating liquid phases of different densities, said apparatus being ofthe kind including a rotatablymounted horizontally-extending shaftproviding a plurality of liquid flow passages therein, liquid seals ateach end of said shaft to permit liquids to be introduced into andremoved from said shaft passages while said shaft is rotating, and arotor casing mounted coaxially on said shaft between said seals andproviding a cylindrical chamber therein, the combination comprising agroup of concentric rings arranged in radially-spaced apart relationwithin said rotor chamber and coaxial to said shaft to provide acontacting and mixing section, said section occupying a zone outwardlyof said shaft and inwardly of the radially outermost wall portion ofsaid casing, said rings providing open cylindrical spaces betweenadjacent rings which extend axially across said contacting and mixingsection and entirely around said rings so that liquids can flow freelyacross and around said spaces, thereby promoting the mixing and intimatecontacting of said liquid phases within said section, said rings havingopenings therethrough for the How of liquids along radial paths inpassing between said cylindrical spaces, a group of vertically-extendingdisks received on said shaft in axiallyspaced apart relation to providea clarifying section within said rotor chamber, said clarifying sectionoccupying a zone between said shaft and said contacting and mixingsection, said clarifying section also being provided with a plurality ofvanes supported within the spaces between said disks, said vanesextending outwardly from said shaft and dividing said disk spaces into aplurality of radiallyextending open-ended segments, thereby permittingthe flow of liquids along radial paths While restricting thecircumferential flow of liquids, said open-ended segments communicatingat one end with the nearest cylindrical space of said contacting andmixing section, said rotor and shaft providing outlet means extendingbetween the other ends of said open-ended segments and one of saidpassages within said shaft, said rotor and shaft having a second outletmeans providing communication between a second of said shaft passagesand the cylindrical space of said contacting and mixing section which isfurthest away from said clarifying section, and said shaft and rotoralso providing inlet means for separately supplying a light liquid phaseand a heavy liquid phase from additional ones of said shaft passages tosaid rotor chamber, said inlet means introducing said heavy phase at aplace outwardly of said shaft and radially inwardly of the place ofintroduction of said light phase, and said places of introduction forsaid light and heavy phases being separated by a plurality of saidrings.

References Cited in the file of this patent UNITED STATES PATENTS1,006,622 Bailey Oct. 24, 1911 2,731,331 Strezynski .Jan. 17, 19562,758,784 Podbielniak et a1. Aug. 14, 1956 3,027,390 Thurman Mar. 27,1962 FOREIGN PATENTS 75,469 Netherlands Aug. 16, 1954

